Control and/or monitoring device using an electronic label, a reader and a state encoder

ABSTRACT

The invention concerns a control and/or monitoring device comprising pairs (P,P′) of interactive members ( 1, 2; 1′, 2′ ) each of which includes an electronic label ( 1, 1′ ) identified by a specific identification code (KID 1,  KID 1′ ) and a reader ( 2, 2′ ) communicating with said label ( 1, 1′ ). For each pair (P) of interactive members, the inventive device also comprises a state encoder at least partially borne by the label ( 1 ), said encoder producing a state signal which is accessible to the reader ( 2 ) and representing a logic or analog state affecting the label ( 1 ) or a relationship between the label ( 1 ) and the reader ( 2 ).

The invention concerns, generally, the sector of informationtechnologies and in particular that of the identification by radiofrequency, known under the Anglo-Saxon acronym RFID (for “RadioFrequency Identification”).

More precisely, the invention relates to a control and/or monitoringdevice including at least a first pair of interactive elements made ofan electronic label and of an electronic tag reader in mutualcommunication by means of respective radio aerials, the reader feedingthe label with electrical energy in an electro-magnetic way and thelabel comprising a memory in which is saved an identification code whichis specific to it and that it selectively transmits to the reader.

The electronic labels, still called “radio tags”, “smart tags”, or“smart cards”, an Anglo-Saxon equivalent name to “étiquettesintelligentes”, are today largely used in many automatic identificationapplications and in particular in the theft security system, thecounterfeit protection, the management of materials handling supports,the control of goods dispatching or reception, etc.

The invention, which is based on the identification of a need until nowlatent, aims at widening the application field of these labels.

For this purpose, the invention device, otherwise in accordance with thegeneric definition given by the above mentioned preamble, is primarilycharacterised by the fact that it moreover includes a state encoderbelonging, at least to some extent, to the label and producing a statussignal representative of a logical or analogical status affecting thelabel or a relation between the label and the reader and by the factthat the status signal is transmitted by the label to the reader ordirectly read by this reader.

Thanks to this fixture, the reader disposes, in form of the statussignal, of an information which not only is richer than a simpleidentification code insofar as it is connected to the local physicalenvironment of the label, but which additionally is, by construction,correlated with this identification code.

In an advantageous realisation mode of the invention, the label ismobile compared to the reader, and the status signal is representativeof a relative position of the label compared to the reader.

Under these conditions, the couple formed by the label and the readerfulfil the function that an electrical contact connected to a mechanicalaction fulfils, with the additional advantage that this contact disposesof an own identification thanks to the identification code of the label.

The state encoder can include at least a permanent magnet carried by oneof the elements of the first pair of interactive elements and a magneticfield sensor carried by the other element of this first pair ofinteractive elements.

It is for example possible to provide that the state encoder permanentlyincludes primarily a pair of magnetised tracks, distant the one from theother, carried by the label and a pair of corresponding Hall effectsensors carried by the reader, that the magnetized tracks are laid outcompared to the corresponding Hall effect sensors for a referencerelative position of the label compared to the reader and only for thisposition, and that the status signal takes at least two differentprincipal logical values according to whether the label is or not, inits reference relative position compared to the reader.

A maximum discrimination of the various states can be obtained byproviding that the tracks of the pair of magnetised tracks have reversedpolarities.

In a first possible realization mode, the label is for examplephysically guided, compared to the reader, between the referencerelative position and a plurality of distant positions while passing byat least one of the two intermediate relative positions in each one ofwhose only one magnetized track is detected by a Hall effect sensor andthe status signal takes at least two different secondary logical valuesaccording to whether the label is, or not, in one of the intermediaterelative positions.

The label can thus be guided in translation movement, compared to thereader, along a translation axis, the magnetized tracks being distantone from the other along this translation axis and possibly beinginclined compared to this same translation axis.

In this case, the label takes for example the form of a card, the readerbeing at least partially flat.

In another possible realisation mode, the label is for example guided inrotation, compared to the reader, along a rotational axis, themagnetised tracks being angularly distant one from the other by rotationaround the rotational axis.

In this case, the label takes advantageously a cylindrical form, thereader itself being at least partially cylindrical.

Practically, the reader typically includes a power supply circuit andpulse shaper belonging to the state encoder and connected to the Halleffect sensors and a communication circuit connected to the aerial ofthis reader.

Under these conditions, the communication circuit can adopt, at leastselectively, a passive state and an active state and the status signalcan make the communication circuit go from its passive state to itsactive state at the time of the passage of the corresponding label froma distant relative position to an intermediate relative position.

The invention device appears particularly advantageous if it includesseveral pairs of interactive elements which each one includes anelectronic label and a tag reader, where the readers of the variouspairs of interactive elements are connected to a communication networkand where all the labels of the various pairs have differentidentification codes.

It is then possible to equip this device with a polling circuitconnected to the communication network, communicating periodically witheach reader, each reader reading off the identification code of theassociated label in so far as this reader and the associated label arein their reference relative position, each reader transmitting to thepolling circuit the identification code of the associated label in sofar as it was read off and the polling circuit comparing eachidentification code which is transmitted to him to a memorised referencecode and producing a anomaly signal in the event of absence of the oneof the codes to be compared or of disparity of the compared codes.

Other characteristics and advantages of the invention will clearly arisefrom the description which is made hereafter as an indication and by nomeans restrictive, by reference to the enclosed drawings, in which:

FIG. 1 is a schematic view of an electronic label modified in order tobe adopted in a device according to the invention.

FIG. 2 is a schematic view of an electronic tag reader, modified inorder to cooperate with the label of the FIG. 1 in a device according tothe invention;

FIG. 3A is a schematic view representing a reader and an electroniclabel belonging to a device according to a first possible realisationmode of the invention and being located in a distant relative position;

FIG. 3B is a similar view to that of the FIG. 3A, in which the readerand the electronic label are located in one of their two relativeintermediate positions, which are a priori possible;

FIG. 3C is a similar view to that of the FIGS. 3A and 3B, in which thereader and the electronic label are located in their reference relativeposition;

FIG. 4 is an exploded schematic view and a perspective view representinga reader and an electronic label belonging to a device in accordancewith a second possible realisation mode of the invention and designed toundergo a relative translation;

FIG. 5 is an exploded schematic view and a perspective view representinga reader and an electronic label belonging to a device in accordancewith a second possible realisation mode of the invention and designed toundergo a relative rotation; and

FIG. 6 is a schematic view representing a device according to theinvention in its most accomplished form.

As indicated previously, the invention relates to a device intended tooperate a control and/or monitoring.

This device includes at least a pair P of interactive elements, thispair being made of an electronic label 1 and of a reader 2 of electroniclabel.

In a known manner, this label and this reader are in mutualcommunication by means of respective radio aerials, such as 10 and 20,the reader 2 feeding the label 1 with electrical energy in anelectromagnetic way through these aerials.

Label 1 comprises a multifunction circuit 11 connected to the aerial 10and ensuring at the same time the filtering and the local distributionof electrical energy received on the aerial 10, the communication withthe reader 2 and more generally the local computer resources managementavailable to the label 1.

The multifunction circuit 11 disposes of a memory 111 in which anidentification code KID1 is saved that is specific to the label 1 andwhich is conditionally transmitted to the reader 2 at least on requestof this last.

On its side, the communication reader 2 includes a communication circuit22 connected to the aerial 20 and which is in charge of ensuring at thesame time the energy transfer towards the aerial 20 and the datatransfer to or from this aerial.

The communication circuit 22 is driven by a control circuit 23, whichitself can have an interactive communication with a network display unitcircuit and/or network interface circuit 24.

According to an essential characteristic, the invention device includesmoreover a state encoder for example made of a transducer 3 and of apower supply circuit and pulse shaper 21.

This state transducer, which belongs at least to some extent to thelabel 1, has as a function to produce a status signal, noted STAT,representative of a logical or analogical state specific to the pair Pof interactive elements.

More precisely, the status signal STAT relates to a state affecting thelabel 1 or a relation between the label 1 and reader 2, and this statussignal STAT is transmitted by the label 1 to the reader 2, or directlyread by this reader 2.

If the STAT signal relates to a state affecting the label 1, the STATsignal can represent any physical parameter to which the label 1 issubordinated, for example a pressure, whereas the transducer 3 will becomposed by a pressure transducer.

If the STAT signal relates to a relation between the label 1 and thereader 2, this relation can be composed by a relative position of thesetwo elements, as shown in the FIGS. 1 to 5.

In this case, the label 1 is mobile compared to the reader 2, and theSTAT status signal is then representative of the relative positionadopted at every moment by the label 1 compared to the reader 2.

For example, the state encoder includes one or more permanent magnets,such as 31 a and 31 b, carried by one of the elements of the first pairP of interactive elements, in fact by the label 1 and one or moremagnetic field sensors, such as 32 a and 32 b, carried by the otherelement of this first pair P of interactive elements, in fact by thereader 2.

FIGS. 1 to 3C illustrate a realisation mode in which the transducer 3belonging to the state encoder includes two magnetised tracks, 31 a and31 b, magnetised in a permanent way, distant the one from the other andcarried by the label 1 and two corresponding Hall effect sensors, 32 aand 32 b, carried by the reader 2.

The magnetised tracks 31 a and 31 b are laid out in relation to thecorresponding Hall effect sensors 32 a and 32 b for a reference relativeposition of the label 1 compared to the reader 2, shown in the FIG. 3C,and only for this position.

The Hall effect sensors 32 a and 32 b are connected to a electricalpower supply circuit and pulse shaper 21, which produces the STAT statussignal and provides it to the control circuit 23, this signal taking atleast two different principal logical values, according to whether thelabel 1 is, or not, in its reference relative position compared to thereader 2.

In other words, whatever the number of bits being used to code the STATstatus signal, the code representative of this signal start with a bitof strong weight equal to “1” or with “0” (or the reverse) according towhether the label 1 is, or not, in its reference relative positioncompared to the reader 2.

To increase the number of states likely to be discriminated the onesfrom the others the magnetised tracks 31 a and 31 b have preferablyreversed polarities.

The FIGS. 3A to 3C represent in a simplified way a realisation mode inwhich the label 1 is physically guided compared to the reader 2 and canbe pushed, along a translation axis X, up to its reference positiontowards the force exerted by a spring 6.

The FIG. 3A represents the label 1 in a distant position compared to thereader 2, i.e. in a position in which none of the Hall effect sensors 32a and 32 b detects one of the magnetised tracks 31 a and 31 b and inwhich the aerials 10 and 20 are too much shifted apart, the one comparedto the other, to allow a communication between the reader 2 and thelabel 1.

The FIG. 3B represents the label 1 in a position known as “intermediate”compared to the reader 2, i.e. in a position in which one of the Halleffect sensors 32 a and 32 b detects one of the magnetised tracks 31 aand 31 b, although the aerials 10 and 20 are still too much shiftedapart, the one compared to the other, to allow a communication betweenthe reader 2 and the label 1.

Two intermediate positions are a priori possible, namely the one inwhich the sensor 32 b detects the magnetised track 31 a (FIG. 3B) andthe one in which the sensor 32 a detects the magnetised track 31 b, evenif the relative movement of the label 1 compared to the reader 2 can belimited by stops to prohibit the label to reach for example the secondintermediate position.

The STAT status signal produced by the electrical power supply circuitand pulse shaper 21 takes at least two different secondary logicalvalues, according to whether the label 1 is, or not, in one of theintermediate relative positions.

In other words, whatever the number of bits being used to code the STATstatus signal, the code representative of this signal comprises, afterthe bit of strong weight whose value indicates if the label 1 is, ornot, in its reference relative position compared to the reader 2, asecond bit whose value indicates if label 1 is, or not, in one of itsintermediate relative positions.

If the label 1 is guided in translation movement compared to the reader2 along a translation axis X and, as show in FIGS. 1 to 4, themagnetised tracks 31 a and 31 b are distant the one from the other alongthis translation axis X, as also are the Hall effect sensors 32 a and 32b.

To make the detection via the Hall effect sensors 32 a and 32 b ofmagnetised tracks 31 a and 31 b more progressive, these tracks 31 a and31 b are advantageously tilted compared to the translation axis X.

The label 1 and the reader 2 can assume a priori several forms.

In particular, label 1 can either take the form of a card (FIGS. 1 to3C), in which case the reader 2 is at least partially flat, or acylindrical form (FIGS. 4 and 5), in which case the reader 2 itself isat least partially cylindrical.

Moreover, instead of being guided in translation movement compared toreader 2, the label 1 can be guided in rotational movement compared tothe reader 2 around an axis of rotation Y (FIG. 5), in which case themagnetised tracks 31 a and 31 b are angularly distant the one from theother by rotation around the rotation axis Y, as also are the Halleffect sensors 32 a and 32 b.

To avoid the necessity of supplying the aerial 20 in a permanent way, itcan be convenient to provide that the communication circuit 22 is bydefault in a passive state, in which the aerial 20 is not supplied andthat this communication circuit 22 is only moved to an active state, inwhich the aerial 20 is supplied, for certain relative positions of thelabel 1 compared to the reader 2.

For example, when label 1 moves from a distant relative position to anintermediate relative position, i.e. when the second strong weight bitof the STAT status signal transmitted to the control circuit 23 changesvalue, this control circuit 23 can make the communication circuit 22moves from its passive state to its active state, this operating modeavoiding the permanent feeding of the aerial 20.

The invention device develops the its greatest number of advantages whenit includes (FIG. 6) a communication network 4, for example formed by abus 40 or including it, several pairs of interactive elements 15 such asP and P′ connected to the network 4 and a polling circuit 5 itselfconnected to different pairs of interactive elements P and P′ by meansof the communication network 4.

Each pair of interactive elements, such as P and P′, includes anelectronic label, such as 1 and 1′ and a tag reader, such as 2 and 2′,the readers of the various pairs P and P′ of the interactive elementsbeing connected to the polling circuit 5 by the communication network 4and all the labels of the various pairs P and P′ of the interactiveelements having different identification codes, such as KID1 and KID1′.

The control circuit 23 of each reader, such as 2 or 2′, is for exampleprogrammed so as to transmit to the corresponding label 1 or 1′, bymeans of the communication circuit 22, a transmission request of theidentification code KID1 or KID′ of this label 1 or 1′, when the STATstatus signal received by the control circuit 23 of this reader 2 or 2′indicates that this same reader, and the associated labels 1 or 1′, arein their reference relative position, and only in this case.

If such is the case, the label 1 or 1′ reads its identification codeKID1 or KID1′ in its memory 111 and retransmits it to the associatedreader 2 or 2′.

The reader 2 or 2′, in so far as it has acquired the identification codeKID1 or KID′ of the associated label 1 or 1′, retransmits this code tothe polling circuit 5 by means of the network display unit circuitand/or network interface circuit 24 of this reader and of the network 4.

The polling circuit 5, which communicates periodically with each readersuch as 2 and 2′, is able to receive the identification codeconditionally emitted by each reader and to identify the origin of it.

This polling circuit 5 has a memory 51 in which reference codes such asKMM and KMM′ are saved, each one of these codes being representative ofthe identification code that one of the readers, such as 2 or 2′, isspecifically supposed to emit and these reference codes being memorisedin a given polling order of the various readers.

With the polling of each reader, such as 2 or 2′, the polling circuitcompares the identification code, such as KID1 or KID1′, transmitted bythis reader with the corresponding memorised reference code, KMM orKMM′.

If the identification code KID1 or KID1′ is not provided by the polledreader, which means that this reader and the corresponding label are notin their reference position, or if the identification code KID1 or KID1′provided by the polled reader differs from the code KMM or KMM′ which itshould have produced, which means that an inversion has occurred betweentwo labels, the polling circuit 5 produces a anomaly signal WARN, whosevalue preferably makes it possible to distinguish, the one from theother, these two types of anomaly.

If various identification codes, such as KID1 and KID1′, are provided bythe various polled readers and match with the respective reference codesmemorised, such as KMM and KMM′, the polling circuit 5 continues itsnormal operation and proceeds to a new polling phase.

1-15. (canceled)
 16. A control and/or monitoring device, comprising: atleast a first pair of interactive elements including an electronic labeland an electronic tag reader in mutual communication by respective radioaerials, the reader being operative to electro-magnetically feed theelectronic label with electrical energy, the electronic label having amemory containing an identification code that is specific to the labeland that the label selectively transmits to the reader; and a stateencoder operative to produce a status signal representative of a logicalor analogical state affecting the elements of the first pair ofinteractive elements, the state encoder including at least a permanentmagnet carried by the electronic label and a magnetic field sensorcarried by the reader.
 17. The control and/or monitoring deviceaccording to claim 16, wherein the label is mobile compared to thereader, the status signal being representative of a relative position ofthe label compared to the reader.
 18. The control and/or monitoringdevice according to claim 17, wherein the state encoder includes a pairof magnetized tracks distant from one another carried by the label and apair of corresponding Hall effect sensors, carried by the reader, themagnetized tracks being laid out compared to the corresponding Halleffect sensors for a reference relative position of the label comparedto the reader and only for this position and, the status signal takingat least two different principal logical values, according to whetherthe label is, or is not, in a reference relative position compared tothe reader.
 19. The control and/or monitoring device according to claim18, wherein the tracks of the pair of magnetized tracks have reversedpolarities.
 20. The control and/or monitoring device according to claim19, wherein the label is physically guidable, compared to the reader,between the reference relative position and a plurality of distantpositions while passing by at least one of two intermediate relativepositions, in each one of which only one magnetized track is detected bya Hall effect sensor, the status signal taking at least two differentsecondary logical values, according to whether the label is, or is not,in one of the intermediate relative positions.
 21. The control and/ormonitoring device according to claim 20, wherein the label is guidablein translation movement compared to the reader along a translation axis,the magnetized tracks being distant from one another along thetranslation axis.
 22. The control and/or monitoring device according toclaim 21, wherein the magnetized tracks are tilted relative to thetranslation axis.
 23. The control and/or monitoring device according toclaim 21, wherein the label is card and the reader is at least partiallyflat.
 24. The control and/or monitoring device according to claim 20,wherein the label is guidable in rotation movement relative to thereader along a rotation axis, the magnetized tracks being angularlydistant from one another by rotation around the rotation axis.
 25. Thecontrol and/or monitoring device according to claim 21, wherein thelabel has a cylindrical form and the reader is at least partiallycylindrical.
 26. The control and/or monitoring device according to claim18, wherein the reader includes a power supply circuit and a pulseshaper belonging to the state encoder and connected to the Hall effectsensors, and a communication circuit connected to the aerial of thereader.
 27. The control and/or monitoring device according to claim 26,wherein the label is physically guidable, compared to the reader,between the reference relative position and a plurality of distantpositions while passing by at least one of two intermediate relativepositions, in each one of which only one magnetized track is detected bya Hall effect sensor, the status signal taking at least two differentsecondary logical values, according to whether the label is, or is not,in one of the intermediate relative positions, the communication circuitbeing operative to selectively adopt at least a passive state and anactive state, the status signal making the communication circuit movefrom its passive state to its active state at the moment of passage ofthe corresponding label from a distant relative position to anintermediate relative position.
 28. The control and/or monitoring deviceaccording to claim 16, including several pairs of interactive elements,each one of which pairs includes an electronic label and a tag reader,the readers of the various pairs of interactive elements being connectedto a communication network, all the labels of the various pairs havingdifferent identification codes.
 29. The control and/or monitoring deviceaccording to claim 28, and further comprising a polling circuitconnected to the communication network and operative to communicateperiodically with each reader, each reader being operative to read theidentification code of the associated label as far as the reader and theassociated label are in their reference relative position, each readerbeing operative to transmit to the polling circuit the identificationcode of the associated label as far as it was read, the polling circuitbeing operative to compare each identification code transmitted to itwith a memorized reference code and produces a anomaly signal in theevent of the absence of one of the codes to be compared or in case ofdisparity of the compared codes.